From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DDCF1CD4851 for ; Thu, 14 May 2026 08:20:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 364D96B008A; Thu, 14 May 2026 04:20:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 33CD96B0093; Thu, 14 May 2026 04:20:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 22E486B0095; Thu, 14 May 2026 04:20:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 11ECC6B008A for ; Thu, 14 May 2026 04:20:49 -0400 (EDT) Received: from smtpin19.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9B650402A0 for ; Thu, 14 May 2026 08:20:48 +0000 (UTC) X-FDA: 84765329376.19.B1019CF Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) by imf30.hostedemail.com (Postfix) with ESMTP id DFBCD80002 for ; Thu, 14 May 2026 08:20:46 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=KDwxvaKg; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf30.hostedemail.com: domain of muchun.song@linux.dev designates 91.218.175.188 as permitted sender) smtp.mailfrom=muchun.song@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1778746847; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=eF9zsW7xnXvYZrz7iQ2MKx+MqvnRKTtP5O8YBI2NE3c=; b=envB3OglLwy+VICk/wxJFupfXPx+ELP/oPh2njVW1AvysOFK3/dZ9su/s6RT3wZanIbTsR i68rlhJ5BolVuzlJGdkLCHK9q/UF1nrsiQpuh+g73NXLaiu2dCI1+I/+mK6wQcYjKDUhBn mVbcn2fEB9Yd5Bvim8uZg0NAqieGXMA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1778746847; a=rsa-sha256; cv=none; b=bBv7GwjBxA7yZ4RQiCk03bO642kWNcMmKi1So61hd6t6wKoebMtA1IKobv/Q5oXJ9rAu4S d5/mkjbb7m/KqxZ778He6p+XBEf5cnTpJJfh9X5dhGzHH6ST+Hzwrq5bJ8UFlsiWnQptAy 5EFoNBI5iajJbxsHVetQagw2pPaKct0= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=KDwxvaKg; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf30.hostedemail.com: domain of muchun.song@linux.dev designates 91.218.175.188 as permitted sender) smtp.mailfrom=muchun.song@linux.dev Content-Type: text/plain; charset=us-ascii DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1778746844; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eF9zsW7xnXvYZrz7iQ2MKx+MqvnRKTtP5O8YBI2NE3c=; b=KDwxvaKgh9l7mgpFBVZ+HTHG5TDMhl79lW7K3ZfMryQ5xm+gJinvCPr43E41bc7FSO4UAU xg27y1DxfnLCU6Y5XwSgd/HiNCx2W+k3aOiQfCwlb22XLvPX1xKbHpaPTswYw7yqpDHi4i Qy7K2XvZmO+OLALVUA8mkSffbYKzz3c= Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3864.500.181\)) Subject: Re: [PATCH v2 02/69] mm/hugetlb_vmemmap: Fix __hugetlb_vmemmap_optimize_folios() X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: Date: Thu, 14 May 2026 16:19:58 +0800 Cc: Muchun Song , Andrew Morton , David Hildenbrand , Michael Ellerman , Madhavan Srinivasan , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Nicholas Piggin , Christophe Leroy , Ackerley Tng , Frank van der Linden , aneesh.kumar@linux.ibm.com, joao.m.martins@oracle.com, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <76D9FAE1-7830-495F-A98D-B3F5FC26F9CC@linux.dev> References: <20260513130542.35604-1-songmuchun@bytedance.com> <20260513130542.35604-3-songmuchun@bytedance.com> To: Oscar Salvador X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DFBCD80002 X-Stat-Signature: 9fjqxpdjpgr13ogk5aahqerqdk4r1137 X-Rspam-User: X-HE-Tag: 1778746846-119549 X-HE-Meta: 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 xwdP+NPR CiB1jNctZCDLCey+/mfjxtwEAaUmABuXkijdPBVqK9VewSny3zkkjsx5YGzbXNC7UKY3/WvLBaSHFWYfbfSCtZQNFKJeqa9U47FRrWlUIaik3KNCVCCOFYRQjIIrr+2/Zw22aN2M3YQrFEXI2X3F+A4IZdfB1cZrXfVVipgEHXLetqPQNgSJpsoRwHacqFqWUOK1I33pgjjVroO0UpeZ8J1B29PkjwlsH8h/TDaguufCJB5PTlT4VdxENkxC4MZCn1eoRU5wFekwHMvYFfFQejYyLDpMoilPp/RGvjzkRDNpG1/cEonfKTVLtGw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On May 14, 2026, at 15:56, Oscar Salvador wrote: >=20 > On Wed, May 13, 2026 at 09:04:30PM +0800, Muchun Song wrote: >> __hugetlb_vmemmap_optimize_folios() uses incorrect arguments when = handling >> bootmem HugeTLB folios. >>=20 >> The section number passed to register_page_bootmem_memmap() is = derived from >> the vmemmap virtual address of folio->page instead of the folio PFN, = so the >> bootmem memmap metadata can be registered against the wrong section. = The >> helper is also given HUGETLB_VMEMMAP_RESERVE_SIZE even though it = expects a >> page count, not a size in bytes. In addition, the write-protect range = is >> based on pages_per_huge_page(h), which does not cover the full = HugeTLB >> vmemmap area and can leave part of the shared tail vmemmap mapping = writable. >>=20 >> Fix the section lookup to use folio_pfn(folio), use >> HUGETLB_VMEMMAP_RESERVE_PAGES when registering the reserved memmap = pages, and >> use hugetlb_vmemmap_size(h) for the write-protect range. >>=20 >> Fixes: 752fe17af693 ("mm/hugetlb: add pre-HVO framework") >> Signed-off-by: Muchun Song >=20 > Acked-by: Oscar Salvador Thanks. >=20 > did you observe any Ooops or malfunctioning or was just code = reviewing? Found by LLM (Gemini Pro). When I touched the code here, LLM will report the bug as well, even it = is not introduced by me :) Thanks, Muchun >=20 >=20 >=20 > --=20 > Oscar Salvador > SUSE Labs